Rotary pump



April 2, 1940. .1. B. HAwLEY, JR 2,195,886

Ap y2, 1940. .1. B. HAwLEY, JR

'ROTARY PUMP Filed Dec. 11. 1936 wm/Z, pff M f 4 sneets shee,c 3

J. B. HAWLEY, JR

ROTARY lPUMP Filed Dec.. 11`1936 I .I Il uw.

J. B. H'AwLEY', .IRA

ROTARY PUMP Filed Dec. 11, 19:56

April 2, 1940.

4 SheetlS-vSheel; 4

Patented Apr. 2, 1940 PATENT OFFICE EOTARY Pm John B.' Hawley, Jr.,

Minneapolis, Minn., as-

signor to Reconstruction Finance Corporation,

Minneapolis, Minn., United States a. corporation of the' ApplicationDecember i1, 193s, serial No. 115,363

Z2 Claims.

carrying the same, the bearings for said shafts' and the driving meansfor said shafts being carried in a casing, which casing is divided alonga plane passing approximately through the centers of said shafts wherebythe discharge side of said casing can be bodily removed from the inletside.

It is another object of the invention to provide a rotary pumpcomprising a casing having a shaft journaled therein, a rotor secured tosaid shaft and rotatable in a chamber in said casing and means forpacking said shaft to preventv leakage from said chamber including asleeve tightly fitting said shaft and having a driving connectiontherewith at one'end.

It is still another object of the invention to provide a rotary pumpcomprising a casing having connecting chambers therein ofsemi-cylindrical form, the centers of said chambers being spaced adistance less than the diameter of one of said chambers together` with anovel construction of lining for said chambers.

It is another object of the invention to provide a rotary pumpcomprising a casing, shafts journaled therein, interacting rotors onsaid shafts, l bearings for said shafts carried in said casing, drivinggears forpsaid shafts,'a driving shaft for said gears, bearings for saiddriving shaft, an,

oil pump and means for driving said oil pump from one of said shaftsdisposed at one end of said casing and an auxiliary casing enclosingsaid means whereby all parts are enclosed and oil can be distributedthereto.

These and other objects and advantages of the invention will be fullyset forth in the following description made in connection with theaccompanying drawings, in which like reference 50 I'characters refer tosimilar parts throughout the' several views and in which- Fig. 1 isa'view in side elevation of said pump Vsome parts being broken away andothers .shown ',"inye'rtical section;

` Fig. l2 is a partial view showing afvertical sec- (Cl. 10S-126) tionthrough one end of the casing and illustrating the oil pump and drivingmeans therefor;

Fig. 3 is a view in end elevation of the pump, a small part being brokenaway and another vpart shown in vertical section;

Fig. 4 is a view for the most part'in central horizontal sectionthroughl the driving shafts and rotors; the upper half of the casingbeing removed;

Fig.r5 is a centralvertical section taken on line 5 5 of Fig. 1 asindicated by the arrow;

Fig. 6 is a partial view similar to Fig. 5 illustrating the lining forthe rotor chamber;

Fig. 7 is a vertical section taken on line 1 1 of Fig. 8 as indicated bythe arrow;

, Fig. 8 is a partial view similar toFig. 4 shown on an enlarged scale;v

Fig. 9 is a-vertical section takenuon line 9-9 of Fig. l as indicated bythe arrow; and

Fig. 10 is a partial view in side elevation of a liner member used. I

Referring to the drawings, a pump is shown comprising a casingdesignated vgenerally as Ill. Casing Ill has a base flange IIla whichrests upon the floor or supporting surface. Above flange IIJa are threecylindrical portions I0b extending in directions at right angles to eachother and each having a surrounding and projectingange I0c to which willbe connected the supply members for the liquid to be pumped, whichmembers may be connected to'anges Ille by bolts 'passing through holes-IIld. One of the flanges Ille faces toward one end of the pump and theother twoy flanges I 0c face respectively toward opposite sides of thepump. Frame IU extends upwardly and has a horizontal flange Illedisposed some distance above the flanges IIIc. The frame portion I Ilhas an interior chamber If into which extend the cylindrical passagesthrough portions IIlb. A screen member II formed of comparatively largewire and of rather coarse mesh has bushings IIa secured to its 'endportions, which bushings are fitted into the passages in portions Illb.A similar screen I3 has a bushing I4 secured to its end. tted in theother portion IIlb, which screen I3 extends to and is connected toscreen II. Another screen I2 of the tray type may b used above screens II and I3. Screen I2 is supported in guideways formed by verticallyspaced flanges vI 0h on the inner side of member I 0. Said screencomprises side members I2a shown as made of pipes and transverse spacedmembers 12b shown as wires or rods secured in members I2. A coarsescreen is carried by members I2a and u i2b. Member l@ is provided withopenings through which the screen l2 may be inserted or removed. "Theseopenings are closed by cover members or plates li. Screens li, l2 and i3are preferably made of brass. A frame member i5 is disposed on the topof flange ille centrally thereof and members i6 and il constitutinglower frame and bearing' bracket members are disposed on flange le ateach side of member 45. Members I5, I6 and lll have base flanges whichare secured by a large number of bolts, some of which are shown as lil,to flange lue. Memberi5 also 4has side flanges engaged by side flangeson members i6 and lll and said flanges are connected by a large numberYof bolts, someof which are shown as I9. Member l5 has therein the lowerportions of semi-cylindrical chambers la and said frame member I5 aswell as members i6 and il have upper flanges, the top surfaces of whichare disposed in a horizontal plane passing substantially through thecenters of chambers 15a. Members i6 and il have outwardly extending sideflanges iSa and ila supporting vertical flanges 1Gb and Hb, the latteralso having horizontal flanges at their tops with top surfaces in thesame plane as the top surfaces of the flanges on members l5, A framemember 20 forming a central top chamber and 'discharge 'member restsupon frame member I5 and has a bottom flange connected to the top flangeof member 'i5 by quite a large number of bolts, some of which are shownas 2l. Frame member 2G has therein the upper portions of thesemi-cylindrical chambers iba and a discharge chamber or passage 20aextends upwardly from said chambers through member 2D. Member 2B has acylindrical ange 28h at its top with a top horizontal surface to whichwill be connected the pipes or other members to which the liquid isdischarged. Chamber 20a has lateral outlets 23o which may be used asdischarge outlets if desired. If not so used they will be closed bycover plates which will be bolted to the finished at sides of the casingabout openings 29o. The openings 20c also constitute inspection openingsthrough which the rotors 42 may be seen and inspected. It is obviousthat a lamp can be placed through the opening 20c into chamber 20a sothat such inspection can be made. At the opposite sides of frame member23 are frame members 22 and 23. The frame member 2D has side anges andmembers 22 and 23 constituting upper frame and bearing bracket membershave flanges engaging said ride flanges and connected thereto by quite alarge number of bolts, some of which are shown as 2. Members 22 and 23each have outwardly extending ribbed portions 22a and 23a at the outerends of which are anges 22h and 23h. The outer surface of flange 22h isin the same plane as the outer surface of ange lb and the outer surfaceof flange 23h is in the same plane as the outer surface of flange Hb.Portions 22a and 23a also have bottom anges 22C and 23o resting on theanges at the top of members lh and l'lb and connected thereto by thebolts 2li. Another frame member 25 forming the lower main gear casingsection has a base flange 25a resting on a ange I 0g disposed a shortdistance above flange Illa. Flange 25a is connected to ange lily bybolts 26. Member 25 has a top flange, the top surface of which is in thesame plane as the top surfaces of the anges at the tops of members i5,i8 and il. The plane at the tops' of these flanges is indicated in Fig.

I6 and 11:

aieaees 1 by the line 2li. A frame member 28 forming the upper main gearcasing section rests upon frame member 25 and has a bottom flangeconnected to the top flange of member 25 by the bolts 23. Members 25 and28 have at one side flat vertical surfaces disposed in the same planeand which are engaged by the flanges |61) and 22h respectively. Flanges|617 and 22h are connected to members 25 and 28 by the ybolts 30. Member25 has a ange 25h at one side having a Hat vertical outer surfaceengaged by the outer surface of a flange 3io, of a member 3l forming thelower auxiliary gear casing section and connected thereto by the bolts32. A frame member 33 forming the upper auxiliary gear casing sectionhas a bottom flange resting upon a top flange of member 3l and connectedthereto by bolts 34. These latter flanges meet in a plane which is thesame plane as indicated by line 2 in Fig. 1 and in. which plane the topsurfaces of members i5, i6 and il are disposed. Frame member 33 has aflange at one side engaging the vertical surface of a side flange onmember 28 and connected thereto by the bolts 35. rihe various framemembers described which are bolted together are carefully and accuratelyfinished and located in position by dowel pins. Members i1 and 23 arebored to receive ball bearings 36 in which are journaled shafts 31 and38. Said shafts have reduced threaded portions at their ends receivingthreaded collars 33 engaging the ends of bearings 36. Members I6 and 22are bored to receive ball bearings 40 in. which shafts 31 and 38' arealso journaled. Said shafts have threaded portions adjacent the bearings40 on which are screwed the collars il engaging the ends of bearings 40.Shafts 31 and 38 are thus held from any substantial longitudinalmovement. Shafts 31 and 38 have keys 31a and 38a therein shown as fourin number and rotor members d2 are bored and splined to receive saidshafts and keys and thus be secured to said shafts. Rotors 42 havetherein circumferentially spaced substantially semicylindrical recessesor pockets 42a between which are the radially extending portions orprojections l32b. The outer surfaces of portions 42h are in the surfaceof a cylinder substantially engaging the inner surfaces of liningmembers 43 disposed in the chambers Iba. The shafts 31 and 38 have theircenters spaced a distance considerably less than the internal diameterof the liner members 53. The liner 4members G3 are thus of substantiallysemi-cylindrical shape and the same have surfaces meeting in a verticalplane midway between the axes of shafts 311 and 33. Said liner membersare connected so as to form one integral member by being brazed orwelded together, some of the brazing or welding metal being shown at63a. Said liners are also divided on planes adjacent line 2l, thedivisions as shown in Figs. 5 and 10 extending in a plane making aslight angle with the horizontal. End plates Q8 are positioned in theends of chambers a and as shown in Fig. i these are disposed within theends of liners i3 and act to support said liners. Members "lli aresecured in place by screws d8a extending therethrough into members 22and 23. The liner members i3 and members 48 will be made of bronze orsome similar comparatively soft metal. The rotors @l2 have disposed inportions Eb thereof adjacent each end of the rotor, tubes lil. Tubes 45having semi-cylindrical closed outer ends are slidable in tubes 44 and acoiled compression spring 45 is disposed in said tubes engaging member42 at one end and tube 45 at its other end. The projections 42b areprovided with central slots 42e at their outer sides, which slots havean inner cylindrical portion 42e. Bars 41 fit in said slots and haveinner semi-cylindrical portions 41a disposed in portions 42c but ofsomewhat smaller diameter than the latter. Bars 41 can thus have someinward and outward movement in said slots. Said bars 41 adjacent theirends are cut away as shown at 41b and the tubes 45 'project into thespace in the bar thus formed and engage the inner side of the bar asshown in Figs. 7 and 8. Springs 45 thus act to move bars 41 outwardly.The sides of the projections 42b are further provided with teeth 42d.

The linings 43 have openings 43e at their upperv sides through which theoil.or other liquid is discharged into the chamber a andsaid membershave openings 43h at their bottoms through which the oil or other liquidpumped passes to the rotors from chamber |5f. Frame membersv I1 and 23are provided with bores through which shafts 31 and 38 project from therotor chambers |5a. Frame members I5 and 22 are also provided with boresthrough which said shafts extend at the outer sides of the rotorchambers |5a. Shafts 31 and 35 have sweated thereon sleeves 45. Inpractice these are made of stainless steel and the inner vends of saidsleeves project some distance within the rotor cham\ bers and into boresformed in the ends of the rotors, said sleeves having splines or slots45a in said inner ends into which extend the keys 31a and 38a formed lonsaid shafts. Sleeves 45 will thus rotate with said shafts and rotors.The inner ends of said sleeves are also provided with small annularslots 45b and the metal of the surrounding rotor is swaged into saidslots. The sleeves 49 extend outwardly through the bores in the framemembers and are surrounded by rings of packing material 55. A packinggland 5| which is made of steel in order to get the requisite strengthand rigidity has a bronze lining 52 throughout its bore and extend- 4ingacross its inner end and said gland extends into the bores of the frameand engages the packing 55. The glands 5| extend at opposite sides ofthe shafts as shown in Fig. 9, the same being centrally andlongitudinally split and having end bosses connected by the headed andnutted bolts 53. Headed screws or bolts 54 extend centrally through theglands within the end lugs and are threaded into the frame for forcingthe glands 5| against the packing 55. A tight fit is thus had about theshafts and a seal from the rotor chamber provided." Should any wearoccur on the sleeves 45 said sleeves 'can be removed and replaced.without changing the shafts.

lars 4|.shafts 31 and 35 have tapered portions i.

with keys therein and have secured thereto the lgears v55 and 5|, whichgears are of the same size and mesh with each other. Said shafts Ahavethreaded portions beyond said gears onwhich are screwed the collars 52engaging the outer sides of gears 55 and 5|. Shaft 31 terminates withsaid threaded portion but shaft is continued therebeyond and has anothertapered portion 35h towhich is keyed the hub of a gear 53. Clearl 53 isof the helical type having spaced tooth portions 53a with which meshpinions. 54 secured to a driving shaft 55. Driving shaft 55 is carriedin ball bearings 55 disposed in bores in frame members 25 and 33respectively. Frame member 25 has a hole or bore 25a provided forconstruction purposes and which is closed by a plate 55 secured tolsaidframe. by bolts 55a. A stumng i Shaft 55 extends beyond stuing box1| and is adapted to be driven by some suitable source of power. In Fig.1 said shaft is shown as having a coupling 51 secured thereto alsosecured to a driving shaft 51a which will be driven from some exteriorpower unit. Shaft 38 is provided with a threaded portion beyond gear 53on which is screwed a collar 13 engaging the outer side of gear 53.Frame members 3| and 33 are bored to receive ball bearings 14 in whichshaft 38 is journaled. A bearing cover plate 15 is bolted to the outerside of frame members 3| and 33 by the bolts 15. Shaft 35 projectsbeyond frame members 3| and 33 and has secured thereto a sprocket member11. A chain 15 runs over sprocket member 11 and over a, sprocket member15 securedto the driving shaft of an oil pump 85 having a flange 55asecured to the lower part of frame member 3| by the bolts 8|. Pump 55has an inlet conduit 55h which carries a screen member 52 through whichoil must pass going into said pump 55. 'I'he outer end of pump 80, theend of shaft 35, sprockets 11 and 15 and chain 15 are enclosed by acasing 83 having a surrounding flange 83a bolted to the end of framemembers 3| and 33 by the bolts 54. 'Ihe chamber in frame members 25, 25,3| and 33 which contains the gears 55, 5|', 53 and 54 is adapted tocontain oil to a. considerable height substantially to the levelindicated by line 85 in Fig. 2. A casing 55 is bolted to the end of thecasing or frame opposite that having casing 53 thereon :and thiscasingforms a chamber 85a at said end of the casing. Frame member 25 hasinspection holes in opposite sides thereof closedv by cover plates 51secured thereto by the bolts 58. An apertured lug 3|b is formed at thelower portion of frame member 3| and has therein a plug 89. This openingis provided for draining the oil chamber by means of a hand pump.

Casing member 53 has a projecting boss 53b vthrough which passes a pipe55, the top of the boss being tightly sealed around said pipe by a plate5| bolted to said boss. Pipe 55 has connected thereto another pipe 92which extends to a sight glass cup 53 having a discharge pipe 54extending into an apertured boss 53o at` the top of casing 53. vA handvalve 55 is disposed in the pipe 52. VAnother pipe 55 extends from pipe95 to a sight glass lcup 51 having a discharge pipe 55 extending into anapertured boss 33a on frame member 33. Pipe 55 delivers oil to bearing55 and shaft 55 as well as to the gears 54. A hand valve 59 is disposedin the pipe 95.` A pipe|55 leads from pipe 55 and delivers ollthrough aboss 33h in frame member 33 to the other bearing 55. A relief valve |5|is disposed in pipe |55.l

Another pipe |52 has branches extending to sight glass cups M33 havingdischarge pipes i865 extending into the frame member, 23 and deliveringoil to hearings 36. 'A hand valve i05 is shown as disposed in pipe HG2.Eipes iB extend from the sides of casing 86 being connected in the outerthreaded Yportions of bores 88h and these pipes extend to and dischargeinto the chamber in frame member 25. A pipe H01 extends from ipe 90 to asight glass cup E08 which has a discharge pipe M39 extending into a pipeassembly i lll discharging into the top of casing 28 and onto gears S6and 63. An elbow member Hl is secured to the top of assembly i l and hasan open end forming a vent. A hand valve M2 is disposed in pipe lG'J.

In operation of the pump the same will be driven through the couplingmember 61 which will drive shaft 65. pinion Sli so that shaft 38 isdriven. Shaft 37 is driven through gears 60 and 6l so that the rotormembers d2 are driven in -opposite directions. As therotor membersrevolve the bars or blades W are held out against" the inner surfaces ofliners t3 and the oil to be pumped which enters through the screens Hand I3 and rises in chamber 40j is moved by the projections 42h andcarried upwardly past the rotors. The blades il enter the recesses 62aand the teeth 42d enter the recesses of the other rotor at the uppersides of said teeth. The oil is thus moved in the Well known manner ofsuch pumps. The oil may be discharged under considerable pressure, thepump illustrated in practice being designed to deliver the oildischarged at a pressure of 100 pounds per square inch. 'I'he casing forthe pump as stated is divided along a horizontal plane passingsubstantially through the centers of shafts 31 and 3B. With thisconstruction the bolts securing the casing together at this plane may beremoved and the upper half of the casing lifted bodily from the lowerhalf. This gives access to the shafts, bearings and rotors so that anychanges or repairs can be easily and quickly made. It will also be seenthat the various sections of the frame can be unbolted and separatelyremoved. Thus members 22 and 23 can be separately removed or the centralsection 2Q can be removed.

This is a great advantage as the pumps are used largely in ships such astankers and are disposed in the hold. It is a very desirable featurethat the different frame and. bearing members as well as the differentparts of the gear casing, such as parts 25, 28, 3i and 33, can beseparately removed. By having the split packing glands i they can bemanipulated in a much smaller space than if the glands had continuousanges. The portions 5i of the glands are preferably made from stainlesssteel having a high modulus of elasticity. The bronze bushing 52 formsthe bearing and has, as is well known, small frictinal resistance. Ifthe whole gland were made of bronze it would not be suiciently strongand the ange would bend under stress of bolts 5d. l'f enough metal wereused to give suicient strength the gland would have too great dimensionsand would be objectionably large necessitating a longer frame and longerrotor shafts. By providing the casings 33 and 86 all parts including thelubricating parts are enclosed and ali are contained in an oil chamber.The oil levelin the chamber in casing 85 will be maintained at or abovethe centers of shafts Si! and 38. The lubrieating pump il@ pumps oilfrom the bottom of thef. chamber in casing portions 25 andii and Gear E3will be driven by' as well as the bearings 1li. The oil after beingdelivered to the chamber 86a drains back therefrom into the main oilchamber in casings 25 and 3l through pipes |06. The pump is thuslubricated in all necessary parts by an oil pump enclosed therein anddriven by its own parts. The sprockets Tl and 'i9 and chain 'i8 are alsowell lubricated as the lower part of the chain 18 and sprocket 'i9 aredisposed in oil. Attention is called to the fact that should the oilpipe lines communicating with relief valve IDI become clogged so thatsaid valve IOI would operate, oil would be delivered to gears 63 and 64through pipe 00. This oil would also reach bearings 66. There would thusnot be a stoppage of the oil circulation. The construction of the linermembers i3 is quite efficient. It is also important to have the linersconnected to `maintain proper relation thereof to the rotors. 'Iheprovision of sleeves 39 makes possible an efcient packing method or sealfor the rotor chambers and any wear of rotation is taken by the sleeve,which sleeve can be readily replaced. As stated, no change is thennecessary' in the shaft. 'Ihe greatest stress on the shafts 31 and 38occurs just at the ends of the rotors. If the shafts corrode at thispoint they are apt to fail. In practice two shafts six inches indiameter made of stainless steel became corroded and cracked at the endsof the rotors. By providing the sleeves 89 the corrosion at this pointis prevented so that the shaft is protected at-the point of greateststress.

From the above description it will be seen that applicant has provided avery elcient and improved structure of pump. The pump must be veryaccurately and strongly made. The same has been amply demonstrated inactual practice and found to be very successful and eicient.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the parts, withoutdeparting from the scope of applicants invention, which generallystated, consists in a device capable of carrying out the objects aboveset forth in the parts and combinations of parts disclosed and definedin the appended claims.

V/hat is claimed is: 1: A rotary pump having in combination, a casing, apair of parallel shafts disposed in said casing, bearings for each shaftspaced longitudinally thereof and carried by said casing, interactingrotors secured to said shafts, said casing having matingsemi-cylindrical chambers for said rotors, gears secured to said shaftsand meshing with each other, a driving gear secured to one of saidshafts, a pinion meshing with said driving gear, a shaft carrying saidpinion, bearings in said casing at each side of said pinion for saidlatter shaft, said casing having an inlet opening at one side of saidrotors and an outlet opening at the opposite side of said rotors, saidcasing having a chamber in which said gears, driving gear and pinion aredisposed, said casing and bearings being divided along a plane passingsubstantially through the centers of said three shafts to form two unitswhereby the portion having said discharge outlet therein may beseparated as one unit bodily from the portion having said inlet openingtherein and means connecting the two portions of said casing together.

2. The structure set forth in claim l, the upper part of said casingbeing divided into separately removable parts along vertical spacedplanes.

8. A. rotan-7 pump having :in combination. a

casing, parallel shafts disposed therein one of which constitutes adriving shaft, bearings for each shaft spaced longitudinally thereof andsupported in said casing, interacting rotors secured to said shaftsrespectively, semi-cylindrical chambers in which said rotors aredisposed and said gears, driving gear and pinion are disposed.

an oil pump disposed in the lower part of said casing, means withoutsaid casing connected to said driving shaft and oil pump for driving thelatter, a casing enclosing said means and secured to said firstmentioned casing having a chamber therein communicating with said firstmentioned casing, a casing secured to said first mentioned casing at theopposite ends. of said shafts and having a chamber therein communicatingwith said first mentioned casing, oil being maintained in said firstmentioned casing and means connected to said oil pump and connected tosaid first mentioned casing for distributing oil to the bearings thereinand to said last mentioned chamber.

4. A rotary pump having in combination, a casing having rotor chamberstherein, interacting rotors in said chambers, shafts to which saidrotors are secured, gears connecting said shafts, one of said shaftshaving a large gear connected thereto, a pinion for driving said largegear, a shaft carrying said pinion, said casing having a chamber thereinenclosing said gears, said casing being divided about a horizontal planepassing through the centers of said vshafts and about a .vertical planepassing through said large gear whereby the same is in four parts, saidparts being separately removable.

5. A rotary pumpv havingl in combination, a casing, a pair of parallelshafts disposed in said casing, bearings for each shaft disposedlongitudinally thereof and carried by said casing, interacting rotorssecured to said shafts, one o f said shafts extending beyond saidcasing, and driving means connected to said shaft beyond said casing, anoil pump disposed in saidcasing, a driving shaft for said oil pumpextending beyond said casing, a driving element secured to said lastmentioned shaft without said casing anddriven by said driving meansandra second casing secured to said first mentioned casing and enclosingsaid one shaft and driving means.

6. A rotary pump having in combination, a casing, a pair of parallelshafts disposed in said casing, bearings for each shaft spacedlongitudinally thereofand carried by said casing, interactingrotors-secured to said shafts, semi-cylindrical chambers for saidrotors, gears secured to I said shafts and meshing with each other, adrivlast mentioned chamber, a driving shaft for said oil pump projectingbeyond said casing, a driving element for said oil pump secured to saidlast mentioned shaft and driven by said driving means and a casingenclosing the projecting portion of said shaft andv driving means.

7. A lining for a rotary pump having connecting semi-cylindricalchambers adapted to receive rotors, comprising adjacent semi-cylindricalshells having surfaces meeting in a plane midway of said chambers andbeing rigidly connected at said meeting point, said shells having freeedges in planes adjacent a planepassing through the `axes of saidchambers.

8. A rotary pump having in combination, parallel shafts, coacting rotorssecured to said shafts, semi-cylindrical chambers in which said rotorsrotate, the axes of said shafts being spaced a' distance smaller .thanthe diameter of said chambers, linings for said chambers meeting in aplane midway between the centers of said chambers, said linings beingrigidly connected by metal secured thereto disposed adjacent said planeand being divided along planes adjacent the plane passing through theaxes of said rotors whereby said linings may bey conveniently assembledand disassembled.-

9. In a rotary pump having connecting semicylindrical chambers, a liningadapted to receive rotors comprising adjacent semi-'cylindrical shellsof substantially uniform thickness radially having their axes spaced alesser distance than 'the diameter of said shells and having surfacesparallel to their axes meeting in a plane midway of said chambers, saidshells being rigidly welded together at said meeting plane whereby theinner surfaces of said lining are parallel to the walls 'of saidchambers, said lining having free edges adjacent the plane passingthrough the axes of said chambers.

.10. A rotary pump having inv combination, a 'I rotor'member, asemi-cylindrical chamber inA which said rotoris disposed, said rotorhaving circumferentially spaced projections with radial slots etxendingtherein from their outer sides, said'slots having enlargedsemi-cylindrical inner ends, bars of comparatively soft metal disposedin said slots and having semi-cylindrical inner ends disposed in saidsemi-cylindrical portions of said slots and of smaller diameter thansaid portions and resilient means normally urging said bars outwardly.

12. The structure set forth in claim 11, said last mentioned meanscomprising telescoping tubes and a spring urging one of said tubesagainst said bar, said bar having a recess adjacent one end into whichsaid tube extends.

13. A rotary pump having in combination, a casing, a pair of parallelshafts disposed in said casing, interacting rotors secured respectivelyto said shafts, said casing having a chamber in which said rotors aredisposed having inlet and outlet passages at opposite sides of saidrotors respectively, bearings for said shafts at `one side of andoutside of said chamber, gears secured to said shafts meshing with eachother, e. driving gear secured to one of said shafts, a pinion meshingwith said driving gear, said casing having a chamber in which saidgears, driving gear,` and pinion are disposed, bearings for said shaftsadjacent one side of and communicating with said last mentioned chamberso as to be lubricated by oil therein, a bearing for said one of saidshafts at the otler side of said last mentioned chamber andcommunicating therewith, said casing being divided along a plane passingthrough the axes of said shafts to form two rigid units, the upper ofsaid units being bodily removable whereby said shafts with said gearsand rotors and bearings may be removed.

14. The structure set forth in claim 13 and a shaft carrying saidpinion, spaced bearings for said latter shaft disposed at either side ofsaid last mentioned chamber and communicating therewith. 1

15. A rotary pump having in combination, a casing, a pair of parallelshafts disposed in said casing, said casing having semi-cylindricalchambers therein, interacting rotors secured to said shafts and disposed4in said chambers, gears secured to said shafts and meshing with eachother, a driving gear secured to one of said shafts, a pinion meshingwith said driving gear, said casing having a chamber in which saidgears, driving gear, and pinion are disposed, a`shaft carrying saidpinion, bearings for said first mentioned shafts at one side of saidlast mentioned chamber and communicating therewith, and a bearing forsaid one shaft at the other side of said chamber and communicatingtherewith, said casing being divided into two rigid units along a planeextending through the axes of said shafts, the upper of said units beingbodily removable.

16. The structure set forth in claim 15 and bearings for said lastmentioned shaft disposed at either side of said chamber and pinion andcommunicating with said last mentioned cham` ber.

17. A rotary pump having in combination, a casing, said casing havingmating semi-cylindri- 'cal chambers therein, a pair of-parallel shaftsdisposed in said casing to which said rotors are respectively secured,an outlet passage leading from said chambers above said rotors, an inletpassage leading downward from said rotors, said casing having a slot inthe side thereof communicating with said inlet passage, a screenextending across said inlet passage and removable through said slot,cylindrical inlet passages at either side of said casing communicatingwith said first mentioned inlet passage, and a cylindrical screensecured in said cylindrical passages and extending between the same andthus across said rst mentioned inlet passage.

18. In a rotary pump having connecting semicylindrical chambers, alining for said chambers having an outer surface fitting against thewalls of said chambers and an inner surface parallel to the walls ofsaid chambers, said lining having surfaces meeting in a planeperpendicular to a plane passing through the axes of said chambers andmidway of said axes, said lining being formed aieaeee y as a rigid unitat said meeting sinfanes and having free edges in planes adjacent saidplane passing through the axes of said chambers and at an angle thereto.

19. A rotary pump having connecting semicylindrical chambers, liningmembers for said chambers each comprising a pair of semi-cylindricalshells having inner and outer surfaces parallel to the walls of saidchambers and having edges meeting in a plane extending perpendicular toa plane passing through the axes of said chambers and midway betweensaid axes, said 'shells being rigidly secured together at said meetingplanes, said linings each having free edges at the remote sides of saidchambers extending in planes adjacent said plane passing through theaxes of said chambers, said chambers having end walls perpendiculartosaid axes, end lining plates within said first mentioned linings andsupporting the same disposed against said end walls and screws securingsaid end plates to said end walls.

20. A rotary pump having in combination, a casing, said casing havingmating semi-cylindrical chambers therein, a pair of parallel shaftsdisposed in said casing to which said rotors are respectively secured,an outlet passage leading from said chambers above said rotors, an inletpassage leading downward from said rotors, said casing having a slot inthe side thereof communicating with said inlet passage, and a screenextending across said inlet passage and removable through said slot,said casing having slots at opposite sides in which said screen isslidable.

21. A rotary pump having in combination, a casing, a pair o'f parallelshafts disposed in said casing, bearings for each shaft spacedlongitudinally thereof and carried by said casing, interacting rotorssecured to said shafts, gears secured to said shafts and meshing witheach other, a driving gear of large diameter secured to one of saidshafts, a pinion meshing with said driving gear, said casing having achamber adjacent one end and an outer end wall in which chamber saidgears, driving gear and pinion are disposed, said chamber being adaptedto contain oil, a chamberforming casing secured to said wall into which'said shaft carrying said driving gear projects, an oil pump in saidlast mentioned chamber having a shaft projecting into said lastmentioned casing, a driving means connecting said last mentioned shaftand said shaft carrying said driving gear, said last mentioned casingbeing adapted to contain oil for lubricating said driving means.

22. A rotary pump having in combination, a driven shaft, a rotorconnected to said shaft, a chamber in which said rotor is disposedhaving an end wall with an opening through which said shaft projects, asleeve tting on and secured to said shaft and extending a. shortdistance through said end wall and a short distance into said rotor, acylindrical recess about said sleeve and means for packing said recess,the metal of said rotor extending into said sleeve.

JOHN' B. HAWLEY. JR.

